This is a note to let you know that I've just added the patch titled x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs to the 3.18-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-asm-traps-disable-tracing-and-kprobes-in-fixup_bad_iret-and-sync_regs.patch and it can be found in the queue-3.18 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Date: Mon, 24 Nov 2014 17:39:06 -0800 Subject: x86/asm/traps: Disable tracing and kprobes in fixup_bad_iret and sync_regs From: Andy Lutomirski <luto@xxxxxxxxxxxxxx> commit 7ddc6a2199f1da405a2fb68c40db8899b1a8cd87 upstream. These functions can be executed on the int3 stack, so kprobes are dangerous. Tracing is probably a bad idea, too. Fixes: b645af2d5905 ("x86_64, traps: Rework bad_iret") Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx> Link: http://lkml.kernel.org/r/50e33d26adca60816f3ba968875801652507d0c4.1416870125.git.luto@xxxxxxxxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/kernel/traps.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -387,7 +387,7 @@ NOKPROBE_SYMBOL(do_int3); * for scheduling or signal handling. The actual stack switch is done in * entry.S */ -asmlinkage __visible struct pt_regs *sync_regs(struct pt_regs *eregs) +asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; /* Did already sync */ @@ -413,7 +413,7 @@ struct bad_iret_stack { struct pt_regs regs; }; -asmlinkage __visible +asmlinkage __visible notrace struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) { /* @@ -436,6 +436,7 @@ struct bad_iret_stack *fixup_bad_iret(st BUG_ON(!user_mode_vm(&new_stack->regs)); return new_stack; } +NOKPROBE_SYMBOL(fixup_bad_iret); #endif /* Patches currently in stable-queue which might be from luto@xxxxxxxxxxxxxx are queue-3.18/x86_64-switch_to-load-tls-descriptors-before-switching-ds-and-es.patch queue-3.18/x86-asm-traps-disable-tracing-and-kprobes-in-fixup_bad_iret-and-sync_regs.patch queue-3.18/x86-tls-disallow-unusual-tls-segments.patch queue-3.18/x86-tls-validate-tls-entries-to-protect-espfix.patch queue-3.18/x86-kvm-clear-paravirt_enabled-on-kvm-guests-for-espfix32-s-benefit.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html